Airbag control unit with part number 77960-T6N-A020-M4

What does the airbag control unit 77960-T6N-A020-M4 do?

The airbag control unit 77960-T6N-A020-M4 is the central control unit of the restraint system (SRS) of Honda. It evaluates the signals from the crash sensors, decides in a crash within milliseconds on the triggering of airbags and seatbelt pretensioners, and monitors the system continuously.

If the system detects a fault, it reports it via the airbag warning light. The crash sensors supply measured values; these are processed in the control unit itself.

After an accident, the unit records crash data and locks itself. The next sections explain how this comes about and how a failure is recognised.

Why does the control unit 77960-T6N-A020-M4 fail?

The most common cause for the 77960-T6N-A020-M4 is crash data recorded after an accident, even without an airbag having fired. Other causes are ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data cannot be erased with a normal diagnostic tool, even if you want to reset the memory.

The other causes concern the electronics themselves. Over the years, components can weaken, and moisture can cause corrosion at solder joints or contacts. Voltage spikes, for example from a weak battery or a jump start, add further strain on the unit.

How can you tell that the 77960-T6N-A020-M4 is defective?

On a defective 77960-T6N-A020-M4, the airbag warning light in the instrument cluster stays on permanently or intermittently. In addition, an error message appears, the diagnostic tool does not connect to the control unit, and the fault memory cannot be cleared.

The warning light shows that the system has stored a fault and reports it itself. This sign deserves prompt attention.

As long as the light is on, airbags and seatbelt pretensioners may possibly not deploy in an emergency. A broken wire or a plug with a contact problem can also lie behind the messages, which is why the diagnosis only follows after reading out.

Which vehicles is the 77960-T6N-A020-M4 fitted in?

The control unit 77960-T6N-A020-M4 is fitted in these vehicles: Honda NSX 2nd generation (2016-2022).

The vehicles recorded for this part number follow below.

• Honda NSX 2nd generation (2016-2022)

Compare the part number on the label of the removed unit with this page. This only confirms that it is the right unit. Have the fault memory read out beforehand, because the result shows whether the control unit is faulty or whether a plug or cable is the cause.

How does the repair of the 77960-T6N-A020-M4 work?

First have the fault memory of the 77960-T6N-A020-M4 read out and enclose the log. Then disconnect the battery and remove the control unit before creating a repair order online and sending in the well-packed unit. At Airbag24, testing, repair and function test usually take 3–4 working days.

The sequence is mandatory, because safety is at stake. The removal begins only once the battery has been disconnected.

Airbag24 examines the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test. Your own unit is then sent back.

Our repairs come with 2 years' statutory liability for defects. The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

How does the control unit 77960-T6N-A020-M4 get to Airbag24?

You send the control unit 77960-T6N-A020-M4 as a parcel, or you book a UPS collection for an extra charge. After the repair, Airbag24 sends the unit back by UPS.

Enclose the printed repair order and pack the control unit shock-resistant.